Melena: Causes, Risk Factors, Symptoms, Diagnosis, Treatment and Prognosis

It is a form of bleeding from the digestive system.

It is then the evacuation of black stools due to the blood content.

This type of gastrointestinal bleeding results in expulsing blood from the digestive system: the digestive tract, the bile ducts, or the pancreas.

Furthermore, upper hemorrhages originating in the upper part of the duodenojejunal angle must be distinguished from low hemorrhages (originating below this angle).

The melena is then a low hemorrhage; in most cases, it comes from a hemorrhage in the right corner of the colon.

The causes of the mane

The main reason for developing melena is bleeding, which can start anywhere in the digestive tract, but most often to pathology, leading to the stomach ulcer, the duodenum.

The onset of bleeding can lead to peptic ulcers, tumors, diverticula, and polyps.


In rare cases, black stools occur with diseases of the pancreas or gallbladder.

In childhood, black stools may be associated with Meckel’s protrusion (congenital or acquired pathology of intestinal development).

In addition to internal causes, the disorder can lead to certain medications, bleeding disorders, and lung or nose bleeding (in this case, the person swallows the blood that enters the stomach).

Different causes can give rise to a mane:

  • The presence of a polyp (growth of the intestinal mucosa) or cancer.
  • Diverticular bleeding (caused by small hernias formed in the intestinal wall).
  • Ischemic, infectious, inflammatory, or radiological colitis.
  • A rectal ulcer (especially in the elderly).
  • Hemorrhages caused by hemorrhoids

In rare cases, melena can arise from angiodysplasias, tumors, and ulcerations from non-steroidal anti-inflammatory drugs.

Mane risk factors

People who suffer from disorders in the digestive system have a greater risk of contracting melena (gastric or intestinal ulcer, ischemic colitis, etc.).

In addition, patients of old age are at greater risk of melena.

The symptoms

In case of extensive hemorrhage, the mane manifests as a liquid stool.

If there is no excessive bleeding, the stool is black and retains its shape after defecation.

With an addiction to constipation, the disorder can manifest itself 2-3 days after the bleeding begins.

In most cases, the condition has symptoms unrelated to bleeding: tinnitus, weakness, nausea, loss of consciousness, darkening of the eyes, hot or cold sweats, and paleness.

Usually, these symptoms appear before melena.

If blood loss from the body is less than 500 ml, the disorder occurs without clearly marked symptoms of blood loss.

However, when it is approximately 1L, there may be possible changes in blood pressure in pulse.

Higher blood losses can cause hemorrhagic shock, significantly reduced pressure, loss of consciousness, and reduced or total absence of reflexes.

The clinical signs of melena result in:

  • The emission of black blood, accompanied by a fetid odor, in the stool.
  • An intestinal pain.


The mane is first detected during the fecal examination of the patient.

However, the patient’s diet should be considered if the stool is not present in the stool examination.

The darkening of the stool can be due to the use of specific products such as blueberries, red wine, and beets, as well as certain medications, especially iron, in which case they have a characteristic for the shine of the mane.

A nasogastric lavage can determine if the bleeding is in the upper or lower digestive tract.

Colonoscopy is used to look for the source of bleeding; it can also collect small samples for biopsies.

The diagnosis of the disease is confirmed or reversed after endoscopy.


The management of the treatment of low hemorrhages depends on the origin.

It can be a simple treatment, an endoscopic ablation, or a particular diet to follow. However, it can also be a medical emergency.

The doctor will prescribe or recommend treatment according to the diagnosis; in the case of stomach ulcers caused by non-steroidal anti-inflammatory drugs, these heal when the drug that causes them is stopped.

Some natural medicine studies recommend licorice, nopal, cruciferous, cranberry juice, apricot, and honey for inflammations and gastric and duodenal ulcers.


The disorder is usually caused by severe internal bleeding, which requires urgent medical intervention.

The mane, in addition to bleeding, can cause disability and even cause death.

The predictions depend on the timely detection of the pathology and a set of therapeutic measures to eliminate it.

The melena or black stools is a pathological condition in which black stools are secreted due to the presence of blood in the stomach, altered by the action of gastric juice.